---
title: Assertions
description: "How to set up assertions for your synthetic checks in OpenStatus"
---


import { Image } from 'astro:assets';

import Assertions from '../../../../assets/monitor/assertions.png';

  <Image
    src={Assertions}
    alt="Monitor assertions"
  />



By default we expect the endpoint to return a `200` status code. If you want to check for a different status code you can go to to the `Assertions` tab and add a new assertion.

We support **status code**, **header** and **body string** assertions.

To change assertions for your monitors: _Select a monitor &rarr; Settings &rarr; Timing & Assertions_.

### Status Code Assertions

Define the **status code** you want to check for.

Supports `Equal`, `Not equal`, `Greater than`, `Less than`, `Greater than or equal`, `Less than or equal` assertions.

### Header Assertions

Define the **header** you want to check for.

Supports `Equal`, `Not equal`, `Contains`, `Does not Contain`, `Empty`, `Not empty`, `Greater than`, `Less than`, `Greater than or equal`, `Less than or equal` assertions.

### Body String Assertions

Define the **body string** you want to check for.

Supports `Equal`, `Not equal`, `Contains`, `Does not Contain`, `Empty`, `Not empty`, `Greater than`, `Less than`, `Greater than or equal`, `Less than or equal` assertions.
